Low-water alarm for steam-boilers.



J. L. FITZGERALD. LOW WATER ALARM FOR STEAM BOILERS.

APPLICATION FILED SEPT. 10' 1913."

Patented Mar. 2, 1915.

2 SHEETSSHEET l.

' SuueMo c MLJZgya attowuas,

J. L. FITZGERALD.

LOW WATER ALARM FOR STEAM BOILERS;

APPLICATION FILED SEP'I '.10,1913. 1,1 30,385.

Patented Mar. 2, 1915.

2 SHEETS-SHEET 2.

JOHN L. FITZGERALD, 013 BOSTON, .MAS SACHUSETTS.

Specification of Letters Patent.

" Patented Mar. 2, 1915.

Application filed September 10, 1913. Serial No. 789,128.

Another object of the invention is to pro-v vide a low water alarm soconstructed that it will serve also as an indicator to show at all timesthe level of the water in the boiler,-

The invention also aims to provide a device of the class mentioned whichmay be readily applied to practically any type of steam boiler withoutany material alteration in the const'ruction of the boilerand at littleexpense.

In the accompanying drawings: Figure 1 is a'view in elevation of thealarm applied to a boiler. Fig. 2 is a vertical longitudinal sectionalview through the device. Fig. 3 is a transverse section on the line 33of Fig. 2. Fig. 4. is a similar view on the line 4-4 of Fig. 2. Fig. 5is a plan view of the indicator. Fig. 6 is a transversesection on theline 6-6 of Fig. 2. v

The alarm embodying the present invention includes a tubular casing 1which is fitted through the boiler shell indicated by the referencecharacter B and secured in place in any suitable manner, as illustratedin Fig. 1 of the drawings. At one end the casing 1 is interiorlythreaded as at 2 and fittedin its said end is one branch of a T- shapedcasing section 3. The casing section 3 has a steam inlet branch 4: whichpreferably projects downwardly from the horizontal branchesandiinteriorly and at the upper end of the passage in the branch 4 thesaid casing section is of substantially semispherical formation asindicated at 5, so as to provide a seat for a spherical valve memberwhich will be presently described. The valve member mentioned above isin the nature of a tube 6 provided at a point between its ends with aspherical enlargement 7 fitting within the seat 5 and having an opening8 adapted to register with the upper end of the passage in the inletbranch 4 of the casingsection 3 when the-tube 6 is rotated, it beingobserved that the tube is mounted for rotation in the horizontalbranches of the casing section 3. That one of the branches which isfitted into the end of the tubular casing 1 is interiorly of a diameterto fit the tube 6 of the valve member and in order that the parts may beassembled the other horizontal branch of the section 3 is interiorly ofa. diameterto receive the Spherical enlargement 7. In order thatthe-tube may have bearing in both of the branches, a bushing 8 isthreaded into the last-mentioned branch and cooperates with thespherical enlargement 7 in a manner clearly shown in Fig. 2 of thedrawings. A cap 9 is fitted on to the end of the tubular casing 1opposite the end into which the casing section 3 is fitted, and this capis provided interiorly and axially with an inwardly flared nipple 10which communicates with one end of a steam passageway 11 extendingfromthe cap. The passage 11 is provided with a branch 12 to which isconnected the stem 13 of a whistle 14: constituting the audible signalof the device. The

tube 6 extends axially within the tubular casing 1 andterminates withinthe cap 9 and this end of the tube has fitted to it a cap 15 having atapered nipple 16 which fits frictionally within the nipple 10. By thisconstruction this end of the'tube 6 is supported for rotation and thetube is placed in communication with the steam passage 11 and the-branch12 so that when the tube 6 has been so rotated as to bring the opening 8in registration with the intake branch 4 steam'will be-admitted to thewhistle 14 to indicate low water in the boiler.

For a purpose to be presently explained, the steam pipe 11 is extendedbeyond the branch 12 as indicated at 17 and has fitted to its end a cap18. A collar 19 is fitted on to the second-described branch of thecasing section 3 and projects beyond the branch and is providedexteriorly with a ball race 20. Atwo-part ring consisting of sections 21has its said sections formed with matching ball races 22 and thecontinuous ball race thus formed cooperates with the race 20 ring 21 andserves to hold the sections thereof in assembledrelation and this cap isprovided axially with a short tubular extension i 25, which, as will beobserved from an in spection of Fig. 2, is in axial alinement with thetube 6. A sleeve 26 is provided at one end with a cap portion 27 whichis threaded onto the end of the tube '6, which projects intothecollar.19 and the said sleeve 26 and fits within the tubular extension 25 ofthe cap 24 as clearly shown in the said Fig; 2 and 1n Fig. 6.-

In order thatyretative movement. may-be imparted to the tube 6 as theWater level in the. boiler rises and falls, there is provided a float 27having an arm 28 provided at one end' with a head 29 fitted over thetubular extension 25, of the cap 24, and a pin 30 is fitted throughregistering openings in the head 29, tubularextension 25,-and sleeve 26,

,andxserves to connect the parts torrotation in unison, as will beapparent.

The indicator device includes a stem 31 which at one end is providedwith a square enlargement .32 fitted within the sleeve 26 and providedwith an opening 33 through which the pin 30 projects. lihe other end ot'the stem 31. extends through the cap 18 at the end of the steam pipeextensions 17 and has. fixed upon it a bevel-gear 34. A. bracket 35 issecuredupon the extension 17 and supports the indicator dial 36 in Whichis rotatably mounted. a stem 37. carrying a beveled gear 38,which mesheswith the gear 34., Ari-indicator handor pointer 39is fixed upon the stem37.,and cooperates with the face of the dial 36 to indicate the waterlevel or .the volume of water within the boiler, asmay be desired.

15 rom the. foregoing description of the invention it will be understoodthat when the Water'level falls the tube 6 Will be rotated so as tobring the opening 8 into registration with the upper end of the intakebranch 4:, thereby admitting steam to the whistle it, the parts havingbeen, ofcourse, so adjusted that steam Will not be admitted until thelevel has fallen approximately to the danger point. It will also beapparent that as the float 27 rises and falls the stem 31 will berotated and the indicator hand 39 will move over the face of the dial 36to indicate variations in thewater level or in the volume of waterWithin the boiler, as may be desired.

Having described my invention, what ll an inlet, a steam conducting piperotatahly mounted in the casing and having an opening adapted to bebrought into communication with the inlet, indicator mechanism includingastem extending within the pipe, afloat having an arm, and meansconnecting the arm with the pipe and \stem forro; tating the said pipeand stem. 1

3. lln a low water alarm, a casing having an inlet, a steam conductingpipe rotatably mounted in the casing and having an open ing adapted tobe brought into communication with the inlet, an audible signal incommunication with the pipe, ahead rotatably fitted upon one end-of thecasing and having a tubular extension, the pipe having a portion fittingwithin the extension, indicator mecha nism including an actuating stemextending I through the pipe and having one end fitted within the saidportion of the pipe, afloat having an.- arm provided with a head fittedto the tubular extension of .-.the first-mentioned head, and meansextending through the interfitted elements to connect the stem and pipeforrotation with the casing head upon rise and fall of the float.

In testimony whereof I- afiix my signature in presence of two witnesses.

JOHN L. FITZGERALD. [Ls] Witnesses:

GEORGE H. BROWN, GRAHAM B. Rein.

